[Xen-devel] Fwd: Openindiana, using -machine pc,accel=xen in qemu

[jim burns <jim_burn@xxxxxxxxxxxxx>]

Pls cc me with any replies. 

I didn't get any responses in xen-users, so I'm posting here. My use case is 
as below, but the jist of it is is the qemu option -machine pc,accel=xen meant 
to be usable in standalone qemu, or is it only available from a guest launched 
by xl, or libvirtd via libxl? If the latter, are there any plans to make it 
available as a standalone qemu option? 

Thank you.

----------  Forwarded Message  ----------

Subject: Openindiana, using -machine pc,accel=xen in qemu
Date: Thursday, September 1, 2016
From: jim burns <jim_burn@xxxxxxxxxxxxx>
To: xen-users@xxxxxxxxxxxxx

I have not been able to run OpenSolaris / openindiana (OI) in xen. OI is very 
sensitive to the -machine parm in qemu. You can get grub to come up with hvm, 
and add -v to the kernel line, and see that for -machine xenfv, the messages 
stop / hang right after the printing of the cpuid features, and just before 
pci bus enumeration. Qemu's -machine q35 is not much better. After the cpuid 
features, it complains that the usb controllers ohci / ehci are unusable (no 
SOF? Interrupts), enumerates the keyboard, then hangs. The next messages 
should be about the usb mouse, and pci devices.

Awhile back, Jun 2013, patches were discussed in xen-devel to add an accel= 
parm to the -machine type. I can use -machine pc,accel=kvm:tcg in stand alone 
qemu. Booting under xen, there is no kvm, so the slow tcg emulation is chosen, 
but it works. I can reboot bare-metal, and and kvm works marvelously, but I 
have other guests I want to run under xen.

If I use accel=xen:kvm:tcg, and start my stand alone qemu OI guest as an 
unpriviledged user, it complains about not having access to a priviledged 
interface (xenpriv?), but other wise goes on to reject kvm, and pick tcg - no 
surprise since you need root access to run xl, so why would stand alone qemu 
work? However, when I do run as root, I get the following error:

failed to get HVM_PARAM_IOREQ_PFN
qemu-system-x86_64: failed to get ioreq server info: error 22 
handle=0x562306ea5680
qemu-system-x86_64: xen hardware virtual machine initialisation failed

and then aborts, w/o going on to check kvm or tcg. Any ideas on where the 
error is, how to correct? Any other parms needed in qemu? I've checked the 
qemu-discuss and xen lists. There was one suggestion to use 
'xen_platform_pci=0' in your xen cfg, which changes the -machine from xenfv to 
pc,accel=xen, but the xen guest just aborts in the same place it was hanging 
before. Hence, I'm trying to just use stand alone qemu.

Thx. 
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